Embodiments of the invention are directed, in general, to communication systems and, more specifically, to identifying enhanced version nodes in communication systems.
As newer and newer amendments of standards (like Institute of Electrical and Electronics Engineers (IEEE) 802.11n high throughput and 802.11s mesh networking, for example) are standardized, network scenarios with such enhanced nodes co-existing with legacy nodes will be abundant. Newer amendments of standardized protocols can usually operate significantly more efficiently in the absence of legacy nodes. Also, newer amendments can employ advanced mechanisms if they can identify nodes that support the techniques defined in the amendments. Thus, identifying legacy nodes and nodes supporting various different amendments is important to ensure optimum performance in a network. Additionally, newer amendments like 802.11s mesh can employ advanced mechanisms such as congestion control or reservations if they can silence legacy STAtions (STA)s selectively for a certain duration in time. Selectively silencing or selectively excluding the silencing of a particular class of nodes may be useful in other cases as well. For example, to ensure access or no access for a particular class for fairness policies etc.
In IEEE 802.11 protocol, Silencing of nodes is achieved by setting their Network Allocation Vector (NAV)s to certain duration. The challenge is to set the NAV of a particular group/class of nodes. Even if a packet achieves such selective silencing, a further issue is that the nodes that are not silenced can update the NAVs of the silenced nodes and get them out of their silence mode. Such a behavior is prescribed in 802.11e as NAV may be shorted by transmitting nodes when they end their transmission opportunity (TXOP)s. A TXOP is defined by the start time and a maximum duration.
Thus, there is a need to identify legacy nodes and selectively silencing these nodes.